Dichroic polarizers absorb a specific polarization of light, transmitting the rest; modern nanoparticle polarizers are dichroic polarizers.

Material stress can be quantified in transparent objects using the photoelastic effect. Stressed material becomes birefringent, and the stress and its related birefringence can be measured by using polarized light.

Figure 2: The electric field of circularly polarized light consists of two perpendicular, equal in amplitude, linear components that have a phase of difference of π/2. The resulting electric field describes a circle.

I had one of these I bought on Amazon. After owning it for a while I bought another for my fishing work bench. I highly recomend them.

I forgot to mention that, that I also started using a pair of generic reading glasses for some work, just to....see, how they'd work (pun intended).  I also have started using them for reading.  They're convenient and they do help, too. A seven-dollar buy at Walgreen's.

I also have a lighted magnifier designed like glasses, with arms that fit over your earlobes, and a nose piece.  I don't like it as much as the Optivisor, because I don't like the weight of the eyepiece, which includes the battery case, on the bridge of my nose.

I have one of those lamp/magnifier combos.  And, I use high powered cheap cheaters from dollar store.  If the magnifier is larger than about four inches, then you can see through it when you are wearing strong glasses and see fine- the powers add.

I'm just wondering how usefull the magnifying glass would be and if I should just stick with buying a LED light without the magnifying glass part.

As important as any magnification is lighting.  If the light is too dim, it won't matter if you can see without magnification or not.  My work bench is well-lit, both with general area lighting, and with light I can focus as necessary on any particular spot.

I started with using a desk magnifier and I quickly became frustrated that it didn't have the reach I often needed, and or, it was a pain to reposition. Along with that, it ate up valuable table space. I had the weighted type, not the clamp type. There are pros and cons to that too. I then tried several head mounted magnifiers and I didn't like the weight of them. Ultimately, I migrated over to reader glasses coupled with interchangeable clamp on magnifier lenses. Amazon sells the magnifier system for about $15. For me, it is the perfect answer. They are comfortable, and they keep your field of view wide open. That equates to less bumping of things. Lastly, the kit comes with I think five different lenses, but,  I have never needed to use more than one. Pick the lens that works and then forget about it.

I need a better light for my work bench so I have been looking at different types of LED lights  including the ones that have the big magnifying glass with the LED light around the outside .

For linearly polarized light with intensity I0, the intensity transmitted through an ideal polarizer, I, can be described by Malus’ law,

The two orthogonal linear polarization states that are most important for reflection and transmission are referred to as p- and s-polarization. P-polarized (from the German parallel) light has an electric field polarized parallel to the plane of incidence, while s-polarized (from the German senkrecht) light is perpendicular to this plane.

I strongly recommended you get a bench light with the magnifying lens.  I use mine every time I sit down to work at the bench.  I don't like the Optivisor because the field of vision is tiny, and you have to hold the item very close to your eyes to focus on it.  (At least, my eyes require that.)

I found that I have poor coordination, working with a magnifier close to my hands and the work, and farther from my eyes, than when I have the magnification at my eyes, and I can hold the work at normal arm's length.  I use an Optivisor.  I have no problem with the small field of magnified vision, and it means that I can hold things as I used to, before my vision started to go.  That is, I can hold a figure in one hand, brush in the other, with my arms at about a 45-degree angle at the elbows.

The idea of a positionable light ties in to magnification.  The brighter the working light, the more your eye pupils stop down, giving you greater depth of field.  When you are using magnifiers, or higher diopter cheaters, your depth of field decreases.  Strong light helps improve this narrowed depth of field.

rcguy How many of you use a magnifying glass of some sort for your modeling? I need a better light for my work bench so I have been looking at different types of LED lights  including the ones that have the big magnifying glass with the LED light around the outside . I'm just wondering how usefull the magnifying glass would be and if I should just stick with buying a LED light without the magnifying glass part.  Thanks for your input.

Understanding and manipulating the polarization of light is crucial for many optical applications. Optical design frequently focuses on the wavelength and intensity of light, while neglecting its polarization. Polarization, however, is an important property of light that affects even those optical systems that do not explicitly measure it. The polarization of light affects the focus of laser beams, influences the cut-off wavelengths of filters, and can be important to prevent unwanted back reflections. It is essential for many metrology applications such as stress analysis in glass or plastic, pharmaceutical ingredient analysis, and biological microscopy. Different polarizations of light can also be absorbed to different degrees by materials, an essential property for LCD screens, 3D movies, and your glare-reducing sunglasses.

But everyone will be different, and there is no objective best.  You might find that using a bench-mounted (or stand-mounted) lighted magnifier is easier for you.  In the end, you'll have to try things and find which one is the most comfortable for you.

I use one of those type magnifiers and I find it quite helpful. I find I still leave the old readers on while using it. Seems to sharpen up the view better for me anyway.

Magnifying reader glasses get my vote too.  I have 3X, which is good for most tasks, and 6X which is good for working with smaller details.  The 3X lets you work at a comfortable distance from what you're working on, while the 6X requires you to get in a lot closer.  As for light, I have a nice, bright LED headlamp in addition to my overhead lighting.  This way, getting the light focused where you're looking happens naturally...when you look at something, your head points the light at it.

Figure 3: The electric field of elliptically polarized light consists of two perpendicular linear components with any amplitude and any phase difference. The resulting electric field describes an ellipse.

Unpolarized light can be considered a rapidly varying random combination of p- and s-polarized light. An ideal linear polarizer will only transmit one of the two linear polarizations, reducing the initial unpolarized intensity I0 by half,

After trying out a number of bench- and light-mounted magnifiers over the years, I found I had much better luck -- first with an Optivisor -- then with simple magnifying 'reader' glasses from the drug store. The light and field-of-view are much better, and the 'distance' is always right without having to constantly bob back and forth. (I used the Optivisor for a long time, but the glasses are much more natural, less like 'tunnel vision.')

Implementing polarization control can be useful in imaging applications. By placing a linear polarizer over the light source, the lens, or both, it is possible to eliminate glare and hot spots from reflective objects or bring out surface defects.

Reflective polarizers transmit the desired polarization while reflecting the rest. Wire grid polarizers are a common example of this, consisting of many thin wires arranged parallel to each other. Light that is polarized along these wires is reflected, while light that is polarized perpendicular to these wires is transmitted. Other reflective polarizers use Brewster’s angle. Brewster’s angle is a specific angle of incidence under which only s-polarized light is reflected. The reflected beam is s-polarized and the transmitted beam becomes partially p-polarized.

In order to select a specific polarization of light, polarizers are used. Polarizers can be broadly divided into reflective, dichroic, and birefringent polarizers. More detailed information on which type of polarizer is right for your application can be found in our Polarizer Selection Guide.

However, I mainly use it for the light, very seldom for the magnifier, but in addition to the cheaters I ordinarily wear, in a tough case it is great.

Figure 1: The electric field of linearly polarized light is confined to a single plane along the direction of propagation.

I have one of those adjustable movement fluorescent ring lights with a magnifier, and love it.  Problem is, the switches wear out even before the bulb/starter, probably because of the high voltage spikes.

Polarization is also very important in the chemical, pharmaceutical, and food and beverage industries. Many important chemical compounds, such as active pharmaceutical ingredients or sugar, are “optically active” and rotate polarized light. The amount of rotation is determined by the nature and the concentration of the compound, allowing polarimetry to detect and quantify these compounds.

Birefringent polarizers rely on the dependence of the refractive index on the polarization of light. Different polarizations will refract at different angles and this can be used to select certain polarizations of light.

I need a better light for my work bench so I have been looking at different types of LED lights  including the ones that have the big magnifying glass with the LED light around the outside .

While polarizers select certain polarizations of light, discarding the other polarizations, ideal waveplates modify existing polarizations without attenuating, deviating, or displacing the beam. They do this by retarding (or delaying) one component of polarization with respect to its orthogonal component. To help you determine which waveplate is best for your application, read Understanding Waveplates. Correctly chosen waveplates can convert any polarization state into a new polarization state, and are most often used to rotate linear polarization, to convert linearly polarized light to circularly polarized light or vice versa.

I'm just wondering how usefull the magnifying glass would be and if I should just stick with buying a LED light without the magnifying glass part.

Figure 6: For more information on using polarization to measure stress, read Successful Light Polarization Techniques or Contact Us.

I have one of those also, along with the desktop lamp/magnifier. I found out that if you use the head mounted magnifier along with a desktop magnifier you can get even more magnification with both combined. Plus the desktop magnifier has a built in lamp and virtually eliminates shadows so you can see everything clearly. I love it.

Where θ is the angle between the incident linear polarization and the polarization axis. We see that for parallel axes, 100% transmission is achieved, while for 90° axes, also known as crossed polarizers, there is 0% transmission. In real world applications the transmission never reaches exactly 0%, therefore, polarizers are characterized by an extinction ratio, which can be used to determine the actual transmission through two crossed polarizers.

For the cheaters, I use ones from Dollar Tree (a buck a piece).  I have three sets of different magnifications for different working distances.  They work great.

Light is an electromagnetic wave, and the electric field of this wave oscillates perpendicularly to the direction of propagation. Light is called unpolarized if the direction of this electric field fluctuates randomly in time. Many common light sources such as sunlight, halogen lighting, LED spotlights, and incandescent bulbs produce unpolarized light. If the direction of the electric field of light is well defined, it is called polarized light. The most common source of polarized light is a laser.

Edmund Optics is a leading supplier of optics and optical components, designing and manufacturing a wide array of multi-element lenses, lens coatings, imaging systems, and opto-mechanical equipment. EO’s state of the art manufacturing capabilities combined with its global distribution network has earned it the position of the world’s largest supplier of off-the-shelf optical components. Customers can purchase items by calling 1-800-363-1992, via the catalog or the website at http://www.edmundoptics.com/